Table 1.

Microarray studies in blood of PD used in meta-analysis.

GEO accession no.	No. of samples	Description	Platform	Reference
GSE54536	PD = 4; HC = 4	Untreated sporadic PD Patients (mean Hoehn and Yahr stage = 1)	Illumina HT-12 V4	Alieva et al., 2014
GSE72267	PD = 40; HC = 19	Untreated sporadic PD (mean Hoehn and Yahr stage = 1.4)	Affymetrix Human Genome U133A 2.0 Array	Calligaris et al., 2015
GSE6613	PD = 50; HC = 22	Early stage sporadic PD patients (mean Hoehn and Yahr = 2.3)	Affymetrix Human Genome U133A	Scherzer et al., 2007
GSE57475	PD = 93; HC = 49	Early stage sporadic PD, treated	Illumina HumanHT-12 V3.0	Locascio et al., 2015